"My feet feel really good on the ground," Bullock told the
entertainment news television program Extra. "Someone asked me
[if I wanted to fly in space] and said 'If your son wanted you to
go?' and I said, 'If he asked me to go, if he was already an
adult, I would go if I knew he would be fine if I perished.'"

Russian satellite debris tears apart Stone's space shuttle
as she and veteran commander Matt Kowalsky (Clooney) are outside
servicing the Hubble Space Telescope. Stone is sent tumbling into
space with Kowalsky, who is outfitted with a prototype jetpack,
following after her. [ Watch:
"Gravity" official teaser movie clips ]

In a series of suspenseful clips that were first previewed for
the audience at Comic-Con in San Diego last weekend and then
released online, Stone's and Kowalsky's situation grows
increasingly worse. The teasers, which are referred to as
"events" on the movie's official website, are the first new look
at the film since a
trailer debuted in May.

The first clip, entitled "Detached," begins just as Mission
Control radios the astronauts to abort their work due to the
incoming debris. Moments later, the shuttle is destroyed, as is
Hubble, and Stone is thrown "off structure," flailing off into
outer space while still attached to the shuttle's now broken-off
robotic arm.

In "Drifting," the second clip, Stone is separated from the arm
but is still tumbling head over heels. The view is from inside
Stone's helmet as she tries to assess her situation. Her attempts
to make radio contact with her fellow shuttle crewmates and
Houston Mission Control go unanswered.

Finally, in "I Got You," Stone and Kowalsky are reunited,
tethered together, and have somehow made it over to the vicinity
of the International Space Station (ISS). Using the last fuel in
his jetpack, Kowalsky propels them toward the orbiting laboratory
in the hopes that one or both of them can grab hold of the
outpost. The stranded spacewalkers' tether snaps in the process,
leading to Stone desperately grasping to reconnect with her
commander.

Were it not for the well-known actors, the clips might pass for
NASA footage. The shuttle "Explorer," Hubble Space Telescope and
International Space Station, as well as the astronauts'
spacesuits and the view of Earth from orbit are all realistically
rendered.

But it's not just the sights that convey a sense of realism, it's
the sounds — or lack thereof.

"In the trailer, they wanted to make it exciting so they put, for
instance, explosions," Cuarón said during a Comic-Con panel
discussion that also included Bullock. "As we know, there is no
sound in space. [In] the film, we don't do that."

Initially, Cuarón wanted to film in actual weightlessness, using
a
plane flying parabolas much in the same way that NASA
astronauts train for their missions and the 1995 film " Apollo 13 "
shot its zero-G scenes. Ultimately though, he opted for a
custom-built rig, which suspended Bullock in a 9-by-9-foot
(2.7-by-2.7-meter) cube while a large robot arm equipped with the
camera pivoted and spun at high speed around her.

"Sandra was completely insulated in that cube," explained Cuarón.
"It took a while for her to get in the rig, so Sandra chose that
in between the takes she would stay there."

"They had me strung up from the 12 wires for eight to nine hours
a day," Bullock said at the Comic-Con panel. "They would just
leave me hanging up there."

Cuarón said the rig was just a means to an end.

"Our focus was not the technology," Cuarón said, "It was her
performance, the emotional journey and how that was going to be
translated [in the film]."

"Gravity" premieres at the Venice Film Festival in Italy on Aug.
28. The 3D movie's North American debut will follow in early
September at the Toronto Film Festival before it opens wide in
theaters on Oct. 4.